Session: 31-03 Compressor Inlet Distortion

Paper Number: 151232

Research on the Anti-Distortion Fan Stator Based on Aerodynamic Performance Analysis Under Inlet Distortion 

The influence of inlet distortion on the aerodynamic performance and stability of fan components in turbofan engines is particularly significant. This paper addresses the issue of inlet distortion in turbofan engines, with a primary focus on investigating the stability of fans operating under distorted conditions. By employing a fan-shaped distortion generator, this study effectively simulates distorted inlet flow fields and assesses the impact of distortion on fan performance under various speeds and operating conditions using unsteady numerical methods.

The numerical results indicate that the non-uniform total pressure distortion induced by the distortion generator initially affects the fan rotor components, exerting a direct influence on the fan's aerodynamic stability. Notably, substantial flow loss occurs near the stator root across different operating conditions and speeds, accompanied by pressure surface separation in certain stator channels. Furthermore, within the central region affected by distortion, flow separation is observed on the suction side of the stator channel. An analysis of the flow field near the mid-span and tip regions of the fan demonstrates that the distortion is transmitted from the rotor to the stator, with the circumferential region affected by the distortion remaining relatively constant, though its effects are more pronounced in the stator region.

Based on this analysis of the distorted flow field, the study proposes a corresponding anti-distortion strategy for the fan stator to counteract the distortion and improve fan performance. By sequentially adjusting geometric angles, uniform pitch, and alternating pitch, optimal stator configurations were identified (corresponding to the Case-β1k, Case-Ut, and Case-At schemes, respectively). Compared to the original fan (ORI), the total pressure loss coefficients of these control schemes were reduced by 7.28%, 7.81%, and 8.98%, respectively, while the blockage coefficients were reduced by 2.95%, 4.25%, and 5.05%. Of these, the Case-At scheme, which incorporates multi-level and multi-parameter regulation, proved most effective in reducing losses and enhancing the flow capacity of the stator passage.

The fan operating characteristic curves obtained for the ORI and Case-At schemes demonstrate that, compared to the ORI, the Case-At scheme substantially improved fan performance, enhancing stability under variable speed conditions and increasing aerodynamic efficiency. At three operating speeds, the Case-At configuration increased stability margins by 10.31%, 8.31%, and 7.39%, respectively, significantly expanding the safety margin under inlet distortion and ensuring reliable operation under these challenging conditions.

Presenting Author: Junyang Yu College of Safety Science and Engineering, Civil Aviation University of China

Presenting Author Biography: Research direction: Numerical investigation of unsteady flow characteristics in fans and compressors, coupled with research on the safety and airworthiness of aviation engines. This primarily encompasses flow control of inlet distortion in engine compression components, aerodynamic stability enhancement and efficiency improvement, biomimetic drag reduction, as well as endwall separation flow control technology.

Authors:

Jie Bai Key Laboratory of Civil Aircraft Airworthiness Technology Civil Aviation University of China
Junyang Yu College of Safety Science and Engineering, Civil Aviation University of China
Peng Sun School of Carbon Neutrality Science and Engineering, Anhui University of Science & Technology
Wenguang Fu School of Mechanical Engineering, Dalian University
Tao Zhang Beijing Institute of Power Machinery
Chunxue Wang Beijing Institute of Power Machinery
Wei Zhao Beijing Institute of Power Machinery